An Earth-like exoplanet is found just 4.2 light-years from the sun, a group of international researchers has confirmed. Using the “Rocky Exoplanets and Stable Spectroscopic Observation Ladder Grating Spectrometer” (ESPRESSO), the scientists found that the exoplanet Proxima b, with a mass of 1.17 Earths, is located in a near-habitable zone with a neighboring star (Proxima Centauri), which orbits the neighboring planet every 11.2 days.
Proxima b was first suspected in 2013, and the European Southern Observatory’s high-precision radial velocity planetary searcher (HARPS) spectrometer confirmed in 2016 that Proxima b is not only the closest exoplanet to us, but also looks more like Earth with more accurate measurements.
According to a team led by Alejandro Suarez Mascareo of the Institute of Astrophysics in Canary, the new measurements for Proxima b came from Swiss-made ESPRESSO, a more advanced version of HARPS, with a threefold increase in accuracy. By measuring the radial velocity changes of the neighboring star with 30 cm/s accuracy, the instrument showed that the exoplanet was 1.17 times the mass of Earth, rather than 1.3 times as previously estimated.
The question now is whether Proxima b is livable. Although its distance from the neighboring star is 1/20 of the distance between the Earth and the sun, the adjacent star is a red dwarf star, so Proxima b is in the orbital region of liquid water, where there may be life. However, Proxima b receives 400 times more X-rays than Earth, so other factors need to be studied.
“Is there an atmosphere that can protect the planet from these deadly rays?” Christophe Lovis, a researcher in the Department of Astronomy at UNIGE, said. “If the atmosphere exists, does it contain chemical elements that promote the development of life — oxygen, for example?” How long have these favourable conditions been around? We need to solve all these problems, especially with the help of future instruments, such as the RISTRETTO spectrometer we will have to build to detect the light emitted by Proxima b, and the future ELT 39-meter giant telescope, HIRES, built by the European Southern Observatory in Chile, to be installed on the future ELT 39-meter giant telescope. “
The study was published in the journal Astronomy and Astrophysics.